private function deleteAction()
 {
     $this->page->extra_url = '&action=delete';
     $id = (int) isset($_GET['id']) ? $_GET['id'] : 0;
     $conf_caja = conf_caja::get($id);
     if ($conf_caja && $this->allow_delete && $conf_caja->delete()) {
         $this->new_message("Configuracion de caja eliminada corectamente!");
     } else {
         if (!$this->allow_delete) {
             $this->new_error_msg("No tiene permisos para eliminar en esta página");
         }
         $this->new_error_msg("Error al eliminar configracion de caja!");
     }
     $this->indexAction();
 }
 /**
  * Return weather a caja should be closed or not according to information on configuration page
  * @return bool
  */
 public function is_usable()
 {
     $info = conf_caja::get_info();
     $dateStart = DateTime::createFromFormat('H:i:s', $info->getStartTime());
     $dateEnd = DateTime::createFromFormat('H:i:s', $info->getEndTime());
     $date2 = new DateTime('NOW');
     if ($date2 > $dateEnd && $dateStart < $dateEnd) {
         return false;
     } else {
         return true;
     }
 }